Print the first 30 numbers using the following rules:

• If n is divisible by 3, print "fizz"
• If n is divisible by 5, print "buzz"
• If n is divisible by both, print "fizzbuzz"
• Else, print the number

Factor

: fizzify ( sbuf m n string -- )
    [ divisor? ] dip '[ _ append! ] when drop ;

: fizzbuzz* ( n -- )
    0 <sbuf> swap { 
        [ 3 "fizz" fizzify ]
        [ 5 "buzz" fizzify ]
        [ '[ _ >dec ] when-empty print ]
    } 2cleave ;

: fizzbuzz ( n -- )
    [1..b] [ fizzbuzz* ] each ;

Kitten

Retrieved from: https://github.com/evincarofautumn/kitten/blob/master/examples/fizz-buzz.ktn

define divisible (Int32, Int32 -> Bool +Fail):
  (%) 0 (=)

define fizzbuzz (Int32 -> List<Char>):
  -> n;
  do (with (+Fail)):
    n 5 divisible
    n 3 divisible

  if:
    if: "FizzBuzz"
    else: "Fizz"
  else:
    if: "Buzz"
    else: n show

define fizzbuzzes (Int32, Int32 -> +IO):
  -> c, m;
  c fizzbuzz say
  if (c < m): (c + 1) m fizzbuzzes

1 100 fizzbuzzes

Haystack

fn fizzbuzz(u64: n) {
    n 15 % 0 == if {
        "FizzBuzz" println
    } else n 5 % 0 == if {
        "Buzz" println
    } else n 3 % 0 == if {
        "Fizz" println
    } else {
        n println
    }
}

fn main() {
    0 while dup 100 < do {
        as [i]
        "i: " print i print " -> " print
        i fizzbuzz
        i 1 + 
    } drop
}